Coral sex is a rare and amazing sight. On the Great Barrier Reef, it takes place once a year, in November or December, shortly after a full moon. During the event, called a mass spawning, billions of polyps release in synchrony tiny, bead-like bundles. These bundles, which contain both sperm and eggs, float to the surface and break apart. Most of the gametes become fish food or simply drift away. The lucky ones meet a gamete of the opposite sex and produce a coral embryo.
